Tablet computer for Navigation

[hellosailor]

"Assisted GPS" or "AGPS" in the US market originally meant "We want to suck your blood every month, so we've only installed half a GPS chip in your phone, all it can do is send raw numbers to our servers and if you subscribe, we'll compute your position and send it back to you."
Since then it has expanded into multiple "assist" modes and options. It can mean that you have a full stand-alone GPS, but the cellco can give it a speed boost by assisting it with server information, and letting the GPS work by itself when there's no cellular network to be found. Among other things.
So saying a device has "assisted GPS" is pretty much like seeing a restaurant menu that says "We serve food". Good for morons, not so good for folks who have food allergies or just don't want tofu today.
Assisted GPS - Wikipedia, the free encyclopedia a fast rundown on some of it.

Last year Samsung and AT&T had some problems the hot new Samsung Galaxy phones, which are set up by default to use AGPS instead of standalone GPS. Except, oops, Samsung had them programmed to get assistance from a server that had been shut down before the phones ever shipped. Then they issued an update...and still set the phones to use a server that didn't exist. Needless to say, the GPS performance was somewhat, ah, lacking.

What's for lunch? Soylent Green, YUMMY!

[annasu]

I want to reiterate and build on what schwa said: cell phones/tablets/etc that have GPS chips in them will take a while to locate you in the absence of cellular or Wifi signal. Devices that have cellular connectivity use AGPS to get signal lock, which is why your average smartphone shows you where you are within seconds. A tablet with no such connectivity, on the other hand, would be expected to be much slower. It should locate you, eventually, but you seriously might wait 5-10 minutes for it to get signal. If you are out in the middle of a lake trying to figure out which way to go to get home, 5 minutes is a pretty long time to wait. Once you have signal lock, you should be good to go until you turn it off, at which point you might have to wait to get signal lock again.

A dedicated GPS receiver, on the other hand, will have much better dedicated antennas and algorithms to get lock, despite not using AGPS either.

[hellosailor]

" but you seriously might wait 5-10 minutes for it to get signal. "
Key word, might. Many of the smartphones today have as much or more computer power than a standalone GPS does. With them, the warm locate time for the GPS (with all assistance turned off) is the same 45-60 seconds that it is for many dedicated GPSes. If the unit is started cold, or transported to a different sky view while off, sure the fix time goes up--but the same as with a GPS.
The newer phones are using the same SirfStar3 and 4 chipsets, and equivalents, that new GPSes use. A dedicated GPS may have a bigger antenna, but with a cleaer sky view and no interference, that won't matter. Once there is "enough" signal, either one works.
Of course with a GPS that is in a smartphone or tablet, few users will ever really know if it is slow because the gizmo is running other processes behind your back. There's still only one real CPU in it, and there's almost always something else running besides the app you think is running. That might be why it seems slower. Especially if it is an Android, which sometimes simply goes out to lunch for a while.

[Stumble]

I can tell you from personal experience that the iPad can go from a cold start to a gps lock in around a minute, even when more than 100 miles from a cell tower. Or about the same time it takes for my Garmin handheld.

[Minnewaska]

Originally Posted by Stumble

I can tell you from personal experience that the iPad can go from a cold start to a gps lock in around a minute, even when more than 100 miles from a cell tower. Or about the same time it takes for my Garmin handheld.

That's my experience as well.

I have a blue tooth external receiver as well and never use it. I can't tell the difference.

[LinekinBayCD]

I don't know about all the other brands of tablets but untill Apple comes out with a good sunlight viewable screen, a waterproof and a more durable Ipad, mine with Navionics charts is only a third or fourth team backup to the fixed mount chartplotter and a couple of charting handhelds.

The ipad reminds me of a swiss army knife when it comes to charting / navigation. It's cool to see all the neat things you can do with a swiss army knife but for most tasks a tool dedicated to the task at hand is a far better choice. Love it for email and the internet but not for navigation

[hellosailor]

Well, low-end-cheapie Pantech, which seems to be an AT&T exclusive, has been advertising an 8-inch-ish tablet that has gotten so-so reviews, but claims to be waterproof to one foot for 30 minutes. Not suited for use under water, but as long as the cokets have their plugs in them, totally rain and splash proof. Something like $250 including a free smartphone--before the AT&T monthly usury fees.

And the Panasonic ToughPad, while advertised in a few places, seems to still be vaporware of a much higher quality.

[sjcdwright]

mx mariner for Android tablets uses free NOAA S57 charts and works pretty good .. cost $6.99 not bad

[Familycruisers]

MX Mariner is the best chartplotter for Android right now.
The days of proprietary systems are over. If I cant navigate, surf the net, and watch Netflix, I dont want it!!

[tomperanteau]

MX Mariner looks like a rip off of OpenCPN. Perhaps they have used parts of the code in porting over. Would be a shame of this were true and they are asking $7 to download it.

I'll stick with navigating using OpenCPN, and USB puck, and my laptop or netbook.